BRITISH STANDARD Ventilation for buildings — Air handling units — Rating and performance for units, components and sections ICS 91.140.30 BS EN 13053:2006 +A1:2011 BS EN 13053:2006+A1:2011 National foreword This British Standard is the UK implementation of EN 13053:2006+A1:2011 It supersedes BS EN 13053:2006 which is withdrawn The start and finish of text introduced or altered by amendment is indicated in the text by tags Tags indicating changes to CEN text carry the number of the CEN amendment For example, text altered by CEN amendment A1 is indicated by !" The UK participation in its preparation was entrusted to Technical Committee RHE/2, Ventilation for buildings, heating and hot water services A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 September 2006 © The British Standards Institution 2012 Published by BSI Standards Limited 2012 ISBN 978 580 72803 Amendments/corrigenda issued since publication Date Comments 31 May 2012 Implementation of CEN amendment A1:2011 EUROPEAN STANDARD EN 13053:2006+A1 NORME EUROPÉENNE EUROPÄISCHE NORM July 2011 ICS 91.140.30 Supersedes EN 13053:2006 English Version Ventilation for buildings - Air handling units - Rating and performance for units, components and sections Ventilation des bâtiments - Caissons de traitement d'air Classification et performance des unités, composants et sections Lüftung von Gebäuden - Zentrale raumlufttechnische Geräte - Leistungskenndaten für Geräte, Komponenten und Baueinheiten This European Standard was approved by CEN on 26 June 2006 and includes Amendment approved by CEN on 19 May 2011 CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members Ref No EN 13053:2006+A1:2011: E BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Contents Page Foreword 4 1 Scope 6 2 Normative references 6 3 Terms and definitions 8 4 Symbols and abbreviations 10 5 5.1 5.2 5.2.1 5.2.2 5.2.3 5.2.4 5.3 5.3.1 5.3.2 5.4 5.5 Ratings and performance of the entire air handling unit 13 General 13 Testing of aerodynamic performance 13 Characteristics and quantities 13 Test method 15 Measurement procedure 15 Evaluation of results 17 Testing of acoustic performance 17 General 17 Specific requirements concerning the set-up of acoustic tests 18 Tolerances 22 Test report 23 6 6.1 6.2 6.3 6.3.1 6.3.2 6.4 6.4.1 6.4.2 6.4.3 6.4.4 6.5 6.5.1 6.5.2 6.5.3 6.6 6.6.1 6.6.2 6.7 6.7.1 6.7.2 6.7.3 6.7.4 6.7.5 6.8 6.8.1 6.8.2 6.8.3 6.9 6.9.1 6.9.2 6.10 Ratings and performance of the entire air handling unit 26 General 26 Casing 26 Fan section 28 General 28 !Power input of fans" " 29 Coils 30 General 30 Testing 30 Construction 30 Cooler/Droplet Eliminator 30 Heat recovery sections 31 General 31 Classifications and requirements 31 Testing 34 Damper sections 34 General 34 Requirements and testing 34 Mixing sections 34 General 34 Categories and characteristics 35 Requirements 35 Measurements 37 Field testing of mixing efficiency 38 Humidifiers 38 General 38 Categories 39 Requirements 39 Filter sections 41 General requirements 41 Filters installed in air handling units 42 Passive sound attenuation sections 43 7 Extended hygiene requirements for special applications 43 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) 7.1 7.2 7.3 7.4 7.5 7.6 General 43 Accessibility 43 Smoothness 43 Inspection windows and lights 44 Drainage/prevention of condensation, humidifiers 44 Air leakage 44 8 8.1 8.2 8.3 Instructions for installation, operation and maintenance 44 Installation 44 Operation and maintenance 44 Documentation and labelling 45 Annex A (informative) Air handling units - Heat recovery – Defrosting - Requirements and testing 46 A.1 General 46 A.2 Defrosting 46 A.2.1 Defrosting heat factor 46 A.2.2 Non-cyclic defrosting 46 A.2.3 Cyclic defrosting 46 A.3 Testing 47 A.3.1 Test rig 47 A.3.2 Duty points 48 A.3.3 Test procedures 48 A.3.4 Testing of defrosting heat factor 48 A.3.5 Total measuring time 48 A.4 Test report 49 A.4.1 The heat recovery device 49 A.4.2 The defrosting heat factor 49 Annex B (informative) !Air handling units – Heat recovery – Characteristics" " 50 B.1 Efficiency of the heat recovery 50 B.2 Evaluation 52 B.3 Evaluation of auxiliary energies 52 B.4 Further characteristics 52 B.5 Efficiency 53 B.6 View of yearly energy 53 Bibliography 54 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Foreword This document (EN 13053:2006+A1:2011) has been prepared by Technical Committee CEN/TC 156 “Ventilation for buildings”, the secretariat of which is held by BSI This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2012, and conflicting national standards shall be withdrawn at the latest by January 2012 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights This document supersedes !EN 13053:2006" This document includes Amendment 1, approved by CEN on 2011-05-19 The start and finish of text introduced or altered by amendment is indicated in the text by tags ! " This European Standard is a part of a series of standards for air handling units used for ventilation and air conditioning of buildings for human occupancy It considers the ratings and the performance of air handling units as a whole, the requirements and performance of specific components and sections of air handling units including hygiene requirements The position of this standard in the field of mechanical building services is shown in Figure According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Figure — Position of this standard in the field of mechanical building services BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Scope This European Standard specifies requirements and testing for ratings and performance of air handling units as a whole It also specifies requirements, recommendations, classification, and testing of specific components and sections of air handling units For many components and sections it refers to component standards, but it also specifies restrictions or applications of standards developed for stand alone components This standard is applicable both to standardised designs, which may be in a range of sizes having common construction concepts, and also to custom-design units It also applies both to air handling units, which are completely prefabricated, and to units which are built up on site Generally the units within the scope of this standard include at least a fan, a heat exchanger and an air filter This standard is not applicable to the following: a) air conditioning units serving a limited area in a building, such as fan coil units; b) units for residential buildings; c) units producing ventilation air mainly for a manufacturing process Normative references The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies EN 308, Heat exchangers — Test procedures for establishing performance of air to air and flue gases heat recovery devices EN 779, Particulate air filters for general ventilation — Determination of the filtration performance EN 1216, Heat exchangers — Forced circulation air-cooling and air-heating coils — Test procedures for establishing the performance EN 1751, Ventilation for buildings — Air terminal devices — Aerodynamic testing of dampers and valves EN 1886:1998, Ventilation for buildings — Air handling units — Mechanical performance EN 12792:2003, Ventilation for buildings — Symbols, terminology and graphical symbols EN 13779, Ventilation for non-residential buildings — Performance requirements for ventilation and room-conditioning systems EN ISO 3741, Acoustics — Determination of sound power levels of noise sources using sound pressure — Precision methods for reverberation rooms (ISO 3741:1999) EN ISO 3744, Acoustics — Determination of sound power levels of noise sources using sound pressure — Engineering method in an essentially free field over a reflecting plane (ISO 3744:1994) EN ISO 3746, Acoustics — Determination of sound power levels of noise sources using sound pressure — Survey method using an enveloping measurement surface over a reflecting plane (ISO 3746:1995) EN ISO 5136, Acoustics — Determination of sound power radiated into a duct by fans and other airmoving devices — In-duct method (ISO 5136:2003) BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) EN ISO 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full — Part 1: General principles and requirements (ISO 5167-1:2003) EN ISO 7235, Acoustics — Laboratory measurement procedures for ducted silencers and air-terminal units — Insertion loss, flow noise and total pressure loss (ISO 7235:2003) ISO 5221, Air distribution and air diffusion — Rules to methods of measuring air flow rate in an airhandling duct ISO 5801:1997, Industrial fans — Performance testing using standardized airways !ISO 13348", Industrial Fans — tolerances, methods of conversion and technical data presentation BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Terms and definitions For the purposes of this European Standard, the terms and definitions given in EN 12792:2003 and the following apply 3.1 air handling unit factory made encased assembly consisting of sections containing a fan or fans and other necessary equipment to perform one or more of the following functions: circulating, filtrating, heating, cooling, heat recovery, humidifying, dehumidifying and mixing air 3.2 section of air handling unit functional element of an air handling unit consisting of one or more components in a single casing 3.3 component of air handling unit smallest functional element of an air handling unit 3.4 blow-through unit air handling unit with a section or sections downstream of the supply air fan 3.5 casing of an air-handling unit enclosure of the unit, within which the components are mounted 3.6 openings for outdoor air, supply air, extract air, recirculation air and exhaust air aperture through which air is taken in or discharged from the air handling unit, such as openings for outdoor air, supply air, recirculation air and exhaust air 3.7 damper section section of air handling unit including a damper or valve 3.8 mixing section section where e.g outdoor air flow and the recirculation air flow are mixed in a controlled way The section generally consists of one damper per air flow and a mixing chamber 3.9 filter section section including a filter or filters and an associated filterframe 3.10 heat recovery section section in which heat (and possibly also moisture) is transferred from one airstream into another, either directly or using an intermediary heat transfer medium 3.11 air heating and cooling coils heat exchangers by means of which heat is transferred from a heat transfer medium to air (heating coil) or the other way round (cooling coil) 3.12 sound attenuation section section in which sound transfer into a ductwork or into ambient air is reduced BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) filter class F5 to F9 according to EN 779 When manufacturing air filters, no components or materials may be used which can serve microbes as nutrients The requirements for air tightness, strength, and bypass leakage are specified in EN 1886 The side wall on the service side of the filter section shall be equipped with an inspection door The width and height of the door shall be greater than the external dimensions of the replaceable filter elements There shall be a free space to the side of the access door and immediately upstream of front access filters sufficient to allow unrestricted access for filter removal and replacement The filter section shall be equipped with tapings for a pressure loss gauge/ manometer Additional requirements can be specified which take into account the climatic conditions (e.g low temperatures, moisture, sand, and salt mist) NOTE In cold climates the possible accumulation of rime may require the slight preheating of supply air and where there is excessive mist in outdoor air, the moisture running off the filters can necessitate specific requirements for corrosion protection 6.9.2 Filters installed in air handling units The first filter stage is to be fitted on the intake side, as close as possible to the outer air intake aperture to keep the air treatment elements as clean as possible Additional coarse filters G1 to G4 are permissible The second filter stage is arranged on the output side at the beginning of the supply duct in order to keep the ductwork clean If a single stage filter system is used for supply air system, a minimum of filter class F7 shall be fitted If two-stage filtering is used, the supply air fan shall be arranged between the first and second filter stage To avoid microbial growth on air filters of the second or higher filter stage, the relative humidity in the area of the filter is to be limited to 90 %; dropping below the dew point in the area of the air filter shall always be avoided Air filters shall not be arranged immediately after coolers with dehumidification or after humidifiers (exception – steam humidifiers) If bag filters are used, the filter area should be at least 10 m² per m² equipment cross-section The seals used shall be of a closed cell type, shall not absorb any moisture and shall not form a nutrient substrate for micro-organisms A permanent tight fit shall be guaranteed for the seal (e.g operation from the dusty air side) Starting from a interior height of 1,6 m, the filter chamber should be fitted with an inspection window (sight glass, inside diameter minimum 150 mm) and with light For fan selection purposes the filter pressure loss value at design volume flow shall be the average of the initial and final pressure losses for clean and dust loaded filters The filter section shall be equipped with measuring devices for pressure drop NOTE Variation in volume flow caused by the accumulation of dust should be given in technical specifications If specific tolerances for an application are not specified, ± 10 % based on the average pressure drop is acceptable The pressure loss of a filter section loaded with dust shall not exceed the values given in Table Lower final pressure drops can be also specified where appropriate Filters installed in air handling units used for human occupancy shall be tested and classified according to EN 779 42 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Table — Maximum final pressure drop for filters Filter class Final pressure drop G1 - G4 150 Pa F5 - F7 200 Pa F8 - F9 300 Pa NOTE The final pressure drops tabulated in Table are the typical maximum values for air-handling units in operation and lower than those used in EN 779 for classification purposes, for reasons of energy saving, and the performance obtained from tests according to EN 779 are not necessarily met at these lower pressure drops The following data shall be displayed in a clear, visible form (e.g label) on the filter section: filter class, type of filter medium, final pressure drop On changing the filter, the user shall check and update this information 6.10 Passive sound attenuation sections The performance of sound attenuation sections shall be tested according to EN ISO 7235 Attenuators should be placed immediately adjacent to the source generating the noise to reduce noise emissions and should preferably be installed in the air handling unit immediately before and after the fan On hygiene aspects they shall not be arranged immediately after coolers with dehumidification or other humidifying devices To ensure unhindered inflow and outflow, a minimum distance from other installed components of 1,0 x (inflow) and/or 1,5 x (outflow) maximum splitter thickness shall be provided The individual splitters should be removable for cleaning and shall consist of permanently abrasion-resistant material which is safe from a health point of view No fibres shall be loosened during service The use of splitter cones can reduce the pressure drop 7.1 Extended hygiene requirements for special applications General Air handling units with high hygiene requirements (e.g hospitals, clean rooms, pharmaceutical industries etc.) shall also meet the requirements defined in this clause 7.2 Accessibility The components of air handling units shall be accessible for cleaning purposes through access doors both upstream and downstream, or alternatively they shall be easy and safe to remove 7.3 Smoothness Any half-closed profiles or joints that can accumulate pollutants and dirt and are difficult to clean, shall not be accepted, especially in the cabinet floor All fibrous and porous material, except replaceable components like filter cells, shall be protected by suitable smooth material, which can withstand frequent cleaning Screws and other similar components shall not protrude from the internal walls 43 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) 7.4 Inspection windows and lights All units shall be provided with inspection windows and internal lighting for checking at least the fans, filters, and humidifiers 7.5 Drainage/prevention of condensation, humidifiers For non-pathogenic bacteria contained in the humidifier water used for air handling purposes, the -1 -1 upper limit value is 000 cfu × ml However, from a bacteria concentration of 100 cfu × ml onwards in the humidifier water, the plant should be checked and cleaned NOTE values These are default values – national regulations, standards and guidelines may specify other limit It is reasonable to use ultraviolet sterilizers to reduce the number of bacteria When designing and adjusting them, however, care shall be taken that no ozone is generated and enters the served space Biocides can only be used if, under no circumstances, they are detrimental to the health of the occupants in the areas served by the air handling unit 7.6 Air leakage For installations with high requirements for hygiene or energy economy, shut-off dampers for supply and exhaust air shall meet the air tightness requirement of class The casing air leakage shall not exceed class L2 (R) according to EN 1886 8.1 Instructions for installation, operation and maintenance Installation The air handling unit should be installed according to the manufacturer's instruction The instructions for installation and commissioning should be in accordance with existing standards, codes, and rules The instructions should include information about the space required for maintenance, mounting and supports etc., preferably including detailed drawings and/or technical data Connections to water, drainage, and the electrical supply network should also be presented in detailed drawings The unit should be easy to connect to these networks and also easy to remove if service or repair is needed Air handling units shall be equipped with suitable lifting devices such as crane eyes, wood or pallets for transportation by crane or forklift Components at risk, e.g fans on spring isolators, shall be protected by safety devices during transportation A label should be attached to the unit stating that such devices shall be removed upon installation Particularly sensitive components or attachments in the area of division between pieces of equipment shall be protected from damage by suitable measures (e.g freely accessible fin packages of heat exchangers should be completely covered) 8.2 Operation and maintenance Instructions for operation and maintenance should include: instructions for safe use in service and maintenance; instructions for starting and closing down the equipment; 44 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) instructions for monitoring equipment recommendations for inspection intervals; description of normal operation of the unit, instructions concerning protection and control equipment, instructions for fault finding; service and cleaning instructions including drawings; for components which require periodical servicing or changing, an estimated service schedule and a list of spare parts and accessories are required; estimated schedule for periodical inspections and instrumentation, periodical inspections, For each functional section of the air-handling unit, appropriate instructions for operation and maintenance are required 8.3 Documentation and labelling Air handling units shall have permanently attached type plates with permanent labelling In addition to the manufacturer, type and order number, all the necessary technical data shall also be clearly shown A drawing of the unit with all the main and duct connection dimensions, a design data sheet, a spare part list plus assembly, commissioning and maintenance instructions shall be supplied with the air handling unit 45 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Annex A (informative) Air handling units - Heat recovery – Defrosting - Requirements and testing A.1 General This annex covers the laboratory testing of the correct functioning and energy recovery of air-handling units with air-to-air heat exchangers of category I or II according to EN 308 under conditions where frosting can occur The tests are performed at specified duty points and the result can be used for comparisons and calculations of recovered heat during a longer period (normally one year) NOTE For testing air-to-air heat exchangers, EN 308 describes a method for laboratory testing of leakage, pressure drop and temperature ratio However, in cold climate heat exchangers of category I and II often can have frosting problems Due to the fact that defrosting is a matter of, not only the heat exchanger itself, but also the whole air handling unit, this annex specifies a method for testing the defrosting and frost protection arrangements for air-handling units Frosting can occur at low outdoor temperatures when moisture is added to the air in the building The loss of recovered energy can be considerable The type of heat exchanger, efficiency, and exhaust air temperature can also influence the amount of frosting problems For cross-flow heat exchangers these problems typically occur at outdoor temperatures lower than -5 °C when moisture is added to the air, not only by the emission from human beings but also due to activities and processes such as, cooking, washing and drying A.2 Defrosting A.2.1 Defrosting heat factor k εD = ∑ [q m22,i ⋅ c p2 ⋅ (t 22,i - t 21,i)∆τ i ] - Q defr i=1 (A.1) k q m 11 ∑c p1 ⋅ (t 11,i - t 21,i ) ∆τ i i=1 where εD is the defrosting heat factor; k is the number of measurements within the total measuring time; ∆τ is the sampling interval time, expressed in s; Qdefr is the total energy input for defrosting during one complete frosting/defrosting cycle, expressed in J A.2.2 Non-cyclic defrosting The unit is provided with a continuously working defrosting function which stabilises or avoids frost formation The static pressure difference on the exhaust air side remains unchanged A.2.3 Cyclic defrosting The unit allows for frost formation followed by a defrosting period This results in a cyclic increase/decrease of pressure difference on the exhaust air side 46 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) A.3 Testing A.3.1 Test rig The complete air-handling unit shall operate with its own fans and be installed with external ducts to ensure that the defrosting equipment acts in a similar way to a real installation The total external pressure drop shall be 250 Pa at nominal air flow on both supply air side and exhaust air side The pressure loss coefficient of the external parts of the test rig shall be constant during the test, so that only frosting can influence the air flow Ambient temperature should be (20 ± 3) °C, (see Figure A.1) Key Measurement of air flow Measurement of static pressure Measurement of temperature Defrosting energy 11 12 21 22 Exhaust air in Exhaust air out Supply air in Supply air out Figure A.1 — Test arrangement for defrosting test 47 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) A.3.2 Duty points Heat recovery performance shall be determined for the following two duty points: Air flow NOTE qm2 = qmn Exhaust air qm1 = qmn These are the initial air flows Both air flows may vary during the measurement time Temperature and humidity NOTE Supply air Exhaust air inlet Supply air inlet + 20 °C, 30 % relative humidity - °C Supply air inlet -15 °C Special applications, e.g high exhaust air humidity, other duty points should be considered Sampling for performance testing shall be done during a number of complete defrosting cycles Total testing time shall include at least cycles and the minimum test time shall be hours For non-cyclic defrosting, sampling shall be done under steady state conditions This condition is reached when temperatures are stable and the heat exchanger exhaust pressure drop, ∆p1, does not vary more than % from the mean value during test Functioning of the defrosting equipment shall be controlled at the same duty points When testing a cyclic defrosting arrangement the variation of pressure drop ∆p1 between different cycles shall not exceed % Non-cyclic systems can be considered to meet the requirements if they become stable under operating conditions A.3.3 Test procedures Where appropriate and not otherwise stated, EN 308 shall apply In addition to the applicable requirements in EN 308, the test shall be in accordance with the procedures given in A.3.4 and A.3.5 A.3.4 Testing of defrosting heat factor The mean value of the temperatures in both sections, t11 and t21, shall be adjusted to within °C of the given temperature in A.3.2 during the test The maximum deviation shall be within 1,5 °C from the mean value during the test Any energy input for defrosting shall be taken into account for calculating the defrosting factors The temperatures of the air flows, defrosting energy and pressure drop shall be measured continuously during the test The sampling interval should not exceed 60 s A.3.5 Total measuring time For non-cyclic defrosting the measuring time after reaching steady state condition shall be 30 For cyclic defrosting the total measuring time shall be a minimum of three cycles, according to Figure A.2 48 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Key Measuring time Time s Figure A.2 — Measuring time for cyclic defrosting A.4 Test report A.4.1 The heat recovery device A description shall be made of the defrosting arrangement Any adjustment of parameters to control defrosting such as time and temperatures shall be clearly stated in the report A.4.2 The defrosting heat factor The following parameters shall be presented: nominal value of the parameters at the beginning of the test, the mean value of the parameters, and diagrams showing the parameters as a function of time during the test: qm1 kg x s qm2 -1 Kg x s total measuring time cycle time -1 t11 t21 εD Qdefr ∆p1 °C °C % W Pa 49 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Annex B (informative) !Air handling units – Heat recovery – Characteristics B.1 Efficiency of the heat recovery The thermal quality of a heat recovery system (HRS) is determined considerably by the ratio of thermal changes (ηt) (temperature efficiency) With a possible humidity transmission the efficiency of a heat recovery can be described also by the enthalpy transmission efficiency or the combination of changes of temperature and humidity (humidity efficiency) The temperature efficiency indicates the relationship of the possible temperatures exchange of a HRS to the maximally possible exchange, thus to the temperature potential between outside and exhaust air It results from the heat balances: ηt = use of the HRS / potential of the HRS ηt = Q HRS / Q P (B.1) where Q HRS is the capacity of the HRS, [kW]; Q P is the maximally possible capacity due to the temperature potential, [kW]; with Q HRS = qm2 × cpA × (t22- t21) (B.2) Q HRS = qm2 × (h22- h21) (B.3) or where qm is the mass flow of the air, [kg / s]; cpA is the specific thermal capacity, [kJ / kg K]; t is the temperature of the air, [°C]; h is the enthalpy of the air, [kJ / kg] The maximally possible capacity is formed by the temperature potential, thus the temperature difference between extract air (t11) and outside air (t21), (see Figure B.1) Thus follows: ηt = Q HRS / Q P = qm2 × cpA × (t22- t21) / [qm2 × cpA × (t11- t21) ] (B.4) And the temperature efficiency: ηt = (t22- t21) / (t11- t21) 50 (B.5) BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Figure B.1 — Heat recovery in hx-diagram (winter operation, supply air to be heated after heat recovery to temperature ts) In the case of a possible humidity transmission the efficiency of humidity (ηx) results similarly out: ηx = (x22- x21) / (x11- x21) (B.6) where x is the absolute humidity of the air, [g / kg] Here it is to be noted that the efficiency of the humidity transmission is not constant contrary to the ratio of temperature transmission and strongly depends on the humidity difference between the two air flows This potential κ is calculated by: κ = x11 – x2S (B.7) where x2s is the saturation humidity of the cold air flow x21 With sorptive heat exchangers the potential depends additionally on the temperature difference of the two air flows Summarized thereby the enthalpy efficiency can be calculated with: ηh = (h22- h21) / (h11- h21) (B.8) h = cpA × t + x × (cpS × t + r0) (B.9) with 51 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) where cpA is the specific thermal capacity of air, [kJ / (kg ⋅ K)]; t is the temperature, [°C]; cpD is the specific thermal capacity of water vapour, [kJ / (kg ⋅ K)]; r0 is the heat for vaporization of water, [kJ / kg] Under dry conditions with ∆x = the enthalpy is calculated with: h = cpA × t (B.10) Under this condition the temperature efficiency ηt is equal to the enthalpy efficiency ηth The efficiencies are defined in accordance to EN 308 only on the supply air side, in order to avoid mistakes To definite the efficiencies related to the exhaust air side is possible accordingly B.2 Evaluation Condensation on the exhaust side can be excluded in evaluation due to relatively short time of condensation conditions Therefore the definition of efficiencies under dry conditions is indispensable Under condensation conditions on the exhaust side the efficiency rises clearly by the improved heat transmission and the more favourable temperature differences under the latent enthalpy portion But due to the small frequency (in hours) of these conditions this has hardly an influence on the economic values of the HRS In addition to the thermal efficiency the HRS is determined also by the pressure losses B.3 Evaluation of auxiliary energies The pressure losses of the HRS determine auxiliary energies and work, which are necessary to keep the HRS running These auxiliary energies essentially determined by the electric drives (fans and other energy consuming equipment, e.g pumps) The necessary power input is calculated thereby: Pel = qv × ∆pHRS × / ηD + Pel aux (B.11) where Pel is the electric power input, [W]; qv is the air or media flow, [m³/s]; ∆pHRS is the sum of pressure losses, supply and exhaust, of the HRS, [Pa]; ηD is the system efficiency of the drive system (e.g fans), [./.]; Pel aux is the auxiliary electric power input (e.g pumps, etc.), [W] The ratio between electrical power input and thermal capacities can be described also by a coefficient of performance (ε): ε = Q HRS / Pel (B.12) B.4 Further characteristics Further characteristics of HRS,either on the capacities of the HRS or on the energies or work, which are calculated on yearly basis, can also be defined However, these are not dealt with in this standard 52 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) B.5 Efficiency The efficiency of the HRS can be defined by the thermal and the electrical capacities If no auxiliary energy would be needed to run the HRS, the temperature efficiency would be equal to the thermal efficiency of the HRS The efficiency represents a combined value from the temperature efficiency and the COP (ε): ηe = use of the HRS / potential of the HRS ηe = (Q HRS – Pel) / Q P and ηe = (1 – Pel / Q HRS) / (Q P / Q HRS) ηe = (1 – / ε) / (1 / ηt) ηe = ηt × (1 – / ε) ηe = ηt × (1 – Pel / Q HRS) The representatively annual efficiency should be based on yearly energies (work), related to yearly energy calculations The thermal capacities depend very strongly on the outside temperature, while the electrical capacities of auxiliary energies are relatively constant over the year This method of yearly energy views can be transferred also to further characteristic values of the HRS B.6 View of yearly energy Exactly the same way characteristic values from the total work can be determined after the calculation of the yearly work values This has the advantage of average characteristic values of the HRS This gives a better possibility of the evaluation as capacity-referred characteristic values But these values have a very high influence on the basic conditions of the calculation Yearly work COP: εa = W HRS / W el (B.13) with W = Σ ( Q × t ) [kWh] yearly efficiency: ηea = Use of the HRS / potential of the HRS ηea = (1 – Wel / W HRS) / (W P / W HRS) ηea = ηta × (1 – / εa) yearly efficiency in primary energy: ηea = (1 – f × Wel / W HRS) / (W P / W HRS) ηea = ηt × (1 – f / εa) with f = primary energy factor (e.g f = 2)." 53 BS EN 13053:2006+A1:2011 EN 13053:2006+A1:2011 (E) Bibliography [1] EN 305, Heat exchangers — Definitions of performance of heat exchangers and the general test procedure for establishing performance of all heat exchangers [2] EN 10088-2, Stainless steels — Part 2: Technical delivery conditions for sheet/plate and strip of corrosion resisting steels for general purposes [3] EN 13030, Ventilation for buildings — Terminals — Performance testing of louvres subjected to simulated rain [4] EN 60034-2, Rotating electrical machines — Part 2: Methods for determining losses and efficiency of rotating electrical machinery from tests (excluding machines for traction vehicles) (IEC 60034-2:1972 + IEC 34-2A:1974) [5] EN ISO 9614-1, Acoustics — Determination of sound power levels of noise sources using sound intensity — Part 1: Measurement at discrete points (ISO 9614-1:1993) [6] EN ISO 9614-2, Acoustics — Determination of sound power levels of noise sources using sound intensity — Part 2: Measurement by scanning (ISO 9614-2:1996) [7] EN ISO 9614-3:2002, Acoustics — Determination of sound power levels of noise sources using sound intensity — Part 3: Precision method for measurement by scanning (ISO 96143:2002) [8] ISO 5168, Measurement of fluid flow — Procedures for the evaluation of uncertainties [9] ISO 3966, Measurement of fluid flow in closed conduits — Velocity area method using pitotstatic tubes 54 This page deliberately set blank British Standards Institution (BSI) BSI is the independent national body responsible for preparing British Standards and other standards-related publications, information and services It presents the UK view on standards in Europe and at the international level BSI is incorporated by Royal Charter British Standards and other standardization products are published by BSI Standards Limited Revisions Information on standards British Standards and PASs are periodically updated by amendment or revision Users of British Standards and PASs should make sure 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